Mobile communication method, mobile station, and radio base station

ABSTRACT

In a mobile communication method according to the present invention, a mobile station (UE) transmits uplink data to a radio base station by using an uplink radio resource assigned to the mobile station by predetermined scheduling information, in a predetermined cycle. The method includes the steps: (A) notifying, to the mobile station (UE), the predetermined cycle and information on the uplink radio resource; (B) notifying, to the mobile station (UE), the predetermined scheduling information; and (C) transmitting uplink data in the predetermined cycle by using the uplink radio resource assigned by the predetermined scheduling information, the transmission starting at a certain point determined on the basis of the received predetermined scheduling information. In the step (C), the predetermined scheduling information is discarded, when the information on the uplink radio resource and information notified by the predetermined scheduling information are inconsistent with each other.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 12/989,283, filed on Oct. 22, 2010, which is a National Phaseapplication of PCT/JP2009/058008, which claims priority to JapaneseApplication Nos. 2008-111922, 2008-141685, 2009-102500.

TECHNICAL FIELD

The present invention relates to a mobile communication method in whicha mobile station transmits uplink data to a radio base station in apredetermined cycle by using an uplink radio resource persistentlyassigned to the mobile station, the transmission starting at anassignment starting time. The present invention also relates to a mobilestation and a radio base station.

BACKGROUND ART

A communication method as a successor of the W-CDMA (Wideband-CodeDivision Multiple Access) scheme or the HSDPA (High Speed DownlinkPacket Access) scheme, namely, the LTE (Long Term Evolution) scheme hasbeen considered by the W-CDMA standardization organization 3GPP, and thespecification setting work is underway.

As a radio access method of the LTE scheme, use of the OFDMA in thedownlink and the SC-FDMA (Single-Carrier Frequency Division MultipleAccess) in the uplink is under consideration.

The OFDMA is a method for dividing a frequency band into plural narrowfrequency bands (sub-carriers) and transmitting data loaded on therespective divided frequency bands. In this method, high-speedtransmission is achieved and frequency utilization efficiency isimproved by arranging sub-carriers densely on the frequency bands insuch a manner that the sub-carriers partially overlap but do notinterfere with each other.

The SC-FDMA is a transmission method which reduces interference betweenterminals by dividing a frequency band and transmitting data by usingfrequency bands different among plural terminals. The SC-FDMA has afeature of less fluctuation in the transmission power, which achieveslow power consumption and wide coverage of terminals.

The LTE scheme is a system in which plural mobile stations communicatewith each other by sharing one or more physical channels in both uplinkand downlink.

A channel shared by plural mobile stations is generally called a sharedchannel, which is, in the LIE system, a “Physical Uplink Shared Channel(PUSCH)” in the uplink and a “Physical Downlink Shared Channel (PDSCH)”in the downlink.

Also, such a shared channel is, as a transport channel, an “UplinkShared Channel (UL-SCH)” in the uplink and a “Downlink Shared Channel(DL-SCH)” in the downlink.

In such a communication system using shared channels described above, itis necessary to select which mobile station UE the shared channel is tobe assigned to, and to signal to the selected mobile station UE that theshared channel is assigned thereto, for each sub-frame (1 ms, in the LTEscheme).

In the LTE scheme, a control channel used for the signaling is calledthe “Physical Downlink Control Channel (PDCCH)” or “Downlink L1/L2Control Channel (DL L1/L2 Control Channel)”.

Meanwhile, the processing for each sub-frame of selecting which mobilestation UE the shared channel is to be assigned to is generally calledthe “scheduling”.

In this case, the processing may also be called the “dynamicscheduling”, because the mobile station UE to which the shared channelis assigned is dynamically selected for each sub-frame.

Furthermore, the expression “assigning the shared channel” describedabove may be alternatively expressed as “assigning a radio resource forthe shared channel”.

Information of the physical downlink control channel includes, forexample, the “downlink scheduling information”, the “uplink schedulinggrant”, and the like.

The “downlink scheduling information” includes, for example, regardingthe downlink shared channel, downlink resource block assignmentinformation, UE-IDs, the number of streams, information on the precedingvector, data size, modulation method, information on the HARQ (hybridautomatic repeat request), and the like.

Meanwhile, the “uplink scheduling grant” includes, for example,regarding the uplink shared channel, uplink resource block assignmentinformation, UE-IDs, data size, demodulation method, uplink transmissionpower information, information on demodulation reference signal in theuplink MIMO, and the like.

Note that, the “downlink scheduling information” and the “uplinkscheduling grant” described above may be collectively referred to as“downlink control information (DCI)”.

Note that, a mobile station uses a “UE-ID (RNTI)” in the uplinkscheduling grant or the downlink scheduling to identify whether or notthe uplink scheduling grant or the downlink scheduling is transmitted tothe mobile station itself.

More specifically, CRC bits included in the uplink scheduling grant orthe downlink scheduling are masked by the RNTI of the mobile station ofthe transmission destination.

The mobile station performs a CRC check by use of the CRC bits. Then,when the result of the CRC check is OK, the mobile station determinesthat the uplink scheduling grant or the downlink scheduling istransmitted to the mobile station itself. When the result of the CRCcheck is not OK, the mobile station determines that the uplinkscheduling grant or the downlink scheduling is not transmitted to themobile station itself.

Note that, the CRC bits are bits used for determining whether atransmitted signal is wrongly decoded or correctly decoded.

Accordingly, when a certain mobile station receives a signal in whichthe CRC bits are masked by the RNTI of another mobile station, theresult of the CRC check becomes not OK even if the signal is actuallyreceived without an error.

In addition, the number of bits for the CRC bits and the RNTI is 16bits, for example.

Note that, a mobile station generally attempts to decode 40 uplinkscheduling grants or 40 pieces of downlink scheduling information, forexample, in a single sub-frame.

In this case, the approximately 40 uplink scheduling grants or the 40pieces of downlink scheduling information include a signal actuallytransmitted to the mobile station itself, a signal transmitted toanother mobile station, a signal including only noise without anytransmission signal, and the like, for example.

On one hand, in “Persistent scheduling”, which has been studied for thepurpose of implementing VoIP and the like, a radio base station eNB isconfigured to persistently assign an uplink or downlink radio resource(PUSCH or PDSCH) to the mobile station, in a predetermined cycle,starting at a sub-frame (assignment starting time) specified by a PDCCH(uplink scheduling grant or downlink scheduling information piece). Notethat, the “Persistent scheduling” may be called “Semi-Persistentscheduling”.

Here, the assignment starting time is a sub-frame in which the downlinkscheduling information is transmitted in the case of downlink, and is anuplink transmission sub-frame specified by the uplink scheduling grantin the case of uplink. In addition, the predetermined cycle is 20 ms,for example.

In the “Persistent scheduling”, the uplink scheduling grant or thedownlink scheduling information is transmitted via a PDCCH only for theinitial transmission, and no uplink scheduling grant or no downlinkscheduling information is transmitted via the PDCCH for thetransmissions after the initial transmission. Thus, the radio resources(overhead) required for transmitting the uplink scheduling grants or thedownlink scheduling information can be reduced. As a result, efficientcommunications can be performed.

Note that, as described above, there are two types of the uplinkscheduling grant or the downlink scheduling grant information. One ofthe types is for notifying, to the mobile station, a resource assignmentby the Dynamic scheduling. The other one of the types is for notifying,to the mobile station, a resource assignment by the Persistentscheduling.

In this case, whether the assignment is by the Dynamic scheduling or bythe Persistent scheduling described above is identified on the basis ofan RNTI and the like, for example, the RNTI set in the uplink schedulinggrant or the downlink scheduling information.

More specifically, an RNTI for the Dynamic scheduling and an RNTI forthe Persistent Scheduling are defined, and whether the assignment is bythe Dynamic scheduling or by the Persistent Scheduling is identified onthe basis of the result of the CRC check of the corresponding RNTI.

SUMMARY OF INVENTION Problem to be Solved by the Invention

As described above, whether the uplink scheduling grant or the downlinkscheduling information notifies, to the mobile station, the assignmentby the Dynamic scheduling or by the Persistent scheduling is identifiedon the basis of the RNTI and the like, the RNTI set in the uplinkscheduling grant or the downlink scheduling information.

In addition, the mobile station attempts to decode approximately 40uplink scheduling grants or 40 pieces of downlink scheduling informationin a single sub-frame (within 1 ms).

Here, since each of the number of bits for the CRC bits and the numberof the RNTI bits is 16 bits, the False Alarm occurs with a probabilityof ½¹⁶.

Accordingly, when 40 uplink scheduling grants or 40 pieces of downlinkscheduling information are to be decoded, the probability of theoccurrence of the False Alarm is ½¹⁶×40.

Here, the False Alarm is a phenomenon where, even when a radio basestation transmits no uplink scheduling grant and no downlink schedulinginformation to a mobile station, the mobile station determines that anuplink scheduling grant or a downlink scheduling information istransmitted to the mobile station itself.

In the case of a resource assignment by the Dynamic scheduling, forexample, the influence of the False Alarm is small because the resourceassignment by the uplink scheduling grant or the downlink schedulinginformation is basically limited in the applicable sub-frame.

In the case of a resource assignment by the Persistent scheduling,however, the influence of the False Alarm is considerable. This isbecause the assignment starting time is specified by the uplinkscheduling grant or the downlink scheduling information, and also aradio resource is assigned periodically and persistently, starting atthe assignment starting time by use of the uplink scheduling grant orthe downlink scheduling information.

In particular, in the case of uplink, the mobile station performs uplinktransmission even though a radio base station assigns no radio resourcethereto. Thus, the uplink transmission signal becomes an interferencesignal which interferes with another mobile station in this case, andthe characteristic features of the system degrade considerably.

Note that, the problem associated with the False Alarm described abovemay occur likewise also in a case of a configuration in which it isdetermined on the basis of a specific one bit in the PDCCH, instead ofan RNTI, whether the one bit is the PDCCH giving an instruction topersistently assign a PDSCH (downlink radio resource) for the“Persistent scheduling” or the PDCCH dynamically assigning a PDSCH(downlink radio resource) for normal downlink scheduling.

In this respect, the present invention has been made in view of theaforementioned problem, and an objective of the present invention is toprovide a stable and efficient mobile communication method, a mobilestation, and a radio base station by reducing the probability of theoccurrence of the False Alarm of uplink scheduling grants in the“Persistent scheduling”.

Solution to Problem

A first aspect of the present invention is summarized as a mobilecommunication method in which a mobile station transmits uplink data toa radio base station in a predetermined cycle by using an uplink radioresource persistently assigned to the mobile station, the transmissionstarting at an assignment starting time, the method including the steps:(A1) notifying, from the radio base station to the mobile station, thepredetermined cycle and information on the uplink radio resource; (B1)determining, at the mobile station, the assignment starting time, andstarting the transmission of the uplink data via the uplink radioresource at the assignment starting time, when receiving a persistentassignment signal from the radio base station, wherein, in the step(B1), the mobile station discards the persistent assignment signal, whenthe information on the uplink radio resource and information notified bythe persistent assignment signal are inconsistent with each other.

In the other words, the first aspect of the present invention issummarized as a mobile communication method in which a mobile stationtransmits uplink data to a radio base station by using an uplink radioresource assigned to the mobile station by predetermined schedulinginformation, in a predetermined cycle, the method including the steps:(A2) notifying, to the mobile station, the predetermined cycle andinformation on the uplink radio resource; (B2) notifying, to the mobilestation, the predetermined scheduling information; and (C2) transmittinguplink data in the predetermined cycle by using the uplink radioresource assigned by the predetermined scheduling information, thetransmission starting at a certain point determined on the basis of thereceived predetermined scheduling information, wherein, in the step(C2), the predetermined scheduling information is discarded, when theinformation on the uplink radio resource and information notified by thepredetermined scheduling information are inconsistent with each other.

In the first aspect, the predetermined cycle and the information on theuplink radio resource can be notified by an RRC message; and thepersistent assignment signal can be notified by a downlink controlchannel.

In the other words, in the first aspect, in the step (A2), thepredetermined cycle and the information on the uplink radio resource canbe notified by an RRC message; and in the step (B2), the predeterminedscheduling information can be transmitted to the mobile station via adownlink control channel.

In the first aspect, a range of information to be specified by thepersistent assignment signal can be limited by the information on theuplink radio resource; and in the step (B1), when information notifiedby the persistent assignment signal is not within the limited range ofinformation to be specifiable by the persistent assignment signal, themobile station can determine that the information on the uplink radioresource and the information notified by the persistent assignmentsignal are inconsistent with each other.

In the other words, in the first aspect, in the step (A2), a range ofinformation specifiable by the predetermined scheduling information canbe limited by the information on the uplink radio resource; and in thestep (C2), when information included in the predetermined schedulinginformation is not within the range limited by the information on theuplink radio resource, the information on the uplink radio resource andthe information notified by the predetermined scheduling information canbe determined to be inconsistent with each other.

In the first aspect, the persistent assignment signal, in the otherwords, the predetermined scheduling information can include at least oneof resource block assignment information, a modulation scheme, a datasize, MCS information, transmission format information, transmissionpower control information, information on Cyclic Shift of DemodulationRS, and a CQI request.

A second aspect of the present invention is summarized as a mobilecommunication method in which a mobile station transmits uplink data toa radio base station by using an uplink radio resource assigned to themobile station by predetermined scheduling information, in apredetermined cycle, the method including the steps of: (A) notifying,to the mobile station, the predetermined cycle and information on theuplink radio resource; (B) notifying, to the mobile station, thepredetermined scheduling information; and (C) transmitting uplink datain the predetermined cycle by using the uplink radio resource assignedby the predetermined scheduling information, the transmission startingat a certain point determined on the basis of the received predeterminedscheduling information, wherein the step (C) is performed wheninformation included in the predetermined scheduling informationcoincides with a previously specified content.

In the second aspect, the predetermined scheduling information caninclude at least one of resource block assignment information, amodulation scheme, a data size, MCS information, transmission formatinformation, transmission power control information, information onCyclic Shift of Demodulation RS, and a CQI request.

A third aspect of the present invention is summarized as a mobilestation configured to transmit uplink data to a radio base station in apredetermined cycle by using an uplink radio resource persistentlyassigned to the mobile station, the transmission starting at anassignment starting time, the mobile station including: a persistentcommunication information receiver unit configured to receive thepredetermined cycle and information on the uplink radio resource fromthe radio base station; and a communication unit configured to determinethe assignment starting time, and to start the transmission of theuplink data via the uplink radio resource at the assignment startingtime, when receiving a persistent assignment signal from the radio basestation, wherein the communication unit is configured to discard thepersistent assignment signal, when the information on the uplink radioresource and information notified by the persistent assignment signalare inconsistent with each other.

In the other words, the third aspect of the present invention issummarized as a mobile station configured to transmit uplink data to aradio base station by using an uplink radio resource assigned to themobile station by predetermined scheduling information, in apredetermined cycle, the mobile station including: a receiver unitconfigured to receive the predetermined cycle and information on theuplink radio resource from the radio base station; and a communicationunit configured to transmit uplink data in the predetermined cycle byusing the uplink radio resource assigned by the predetermined schedulinginformation, the transmission starting at a certain point determined onthe basis of the predetermined scheduling information received from theradio base station, wherein the communication unit is configured todiscard the predetermined scheduling information, when the informationon the uplink radio resource and information notified by thepredetermined scheduling information are inconsistent with each other.

In the third aspect, the predetermined cycle and the information on theuplink radio resource can be notified by an RRC message; and thepersistent assignment signal can be notified by a downlink controlchannel.

In the other words, in the third aspect, the receiver unit can beconfigured to receive the predetermined cycle and the information on theuplink radio resource via an RRC message; and the communication unit canbe configured to receive the predetermined scheduling information via adownlink control channel.

In the third aspect, the communication unit can be configured todetermine that the information on the uplink radio resource and theinformation notified by the predetermined scheduling information areinconsistent with each other, when information included in thepredetermined scheduling information is not within a range ofinformation specifiable by the predetermined scheduling information, therange limited by the information on the uplink radio resource.

In the third aspect, the persistent assignment signal, in the otherwords, the predetermined scheduling information can include at least oneof resource block assignment information, a modulation scheme, a datasize, MCS information, transmission format information, transmissionpower control information, information on Cyclic Shift of DemodulationRS, and a CQI request.

A fourth aspect of the present invention is summarized as a mobilestation configured to transmit uplink data to a radio base station byusing an uplink radio resource assigned to the mobile station bypredetermined scheduling information, in a predetermined cycle, themobile station including: a receiver unit configured to receive thepredetermined cycle and information on the uplink radio resource fromthe radio base station; and a communication unit configured to transmituplink data in the predetermined cycle by using the uplink radioresource assigned by the predetermined scheduling information, thetransmission starting at a certain point determined on the basis of thepredetermined scheduling information received from the radio basestation, wherein the communication unit is configured to transmit theuplink data, when information notified by the predetermined schedulinginformation coincides with a previously specified content.

In the forth aspect, the predetermined scheduling information caninclude at least one of resource block assignment information, amodulation scheme, a data size, MCS information, transmission formatinformation, transmission power control information, information onCyclic Shift of Demodulation RS, and a CQI request.

A fifth aspect of the present invention is summarized as a radio basestation to be used in a mobile communication method in which a mobilestation transmits uplink data to the radio base station in apredetermined cycle by using an uplink radio resource persistentlyassigned to the mobile station, the transmission starting at anassignment starting time, the radio base station includes: a persistentcommunication information transmitter unit configured to notify, to themobile station, the predetermined cycle and information on the uplinkradio resource; a persistent assignment signal transmitter unitconfigured to transmit the persistent assignment signal to the mobilestation; and communication unit configured to start reception of theuplink data via the uplink radio resource at the assignment startingtime determined by the persistent assignment signal, wherein thepersistent communication information transmitter unit configured tonotify information limiting a range of information to be specifiable bythe persistent assignment signal, as the information on the uplink radioresource.

In the other words, the fifth aspect of the present invention issummarized as a radio base station used in a mobile communication systemin which a mobile station transmits uplink data to a radio base stationby using an uplink radio resource assigned to the mobile station bypredetermined scheduling information, in a predetermined cycle, theradio base station including: a first transmitter unit configured tonotify, to the mobile station, the predetermined cycle and informationon the uplink radio resource; a second transmitter unit configured totransmit the predetermined scheduling information to the mobile station;and a communication unit configured to receive uplink data transmittedin the predetermined cycle by using the uplink radio resource assignedby the predetermined scheduling information, wherein the firsttransmitter unit is configured to notify, to the mobile station,information limiting a range of information specifiable by thepredetermined scheduling information, as the information on the uplinkradio resource.

In the fifth aspect, the predetermined cycle and the information on theuplink radio resource can be notified by an RRC message; and thepersistent assignment signal can be notified by a downlink controlchannel.

In the other words, in the fifth aspect, the first transmitter unit canbe configured to notify, to the mobile station, the predetermined cycleand the information on the uplink radio resource via an RRC message; andthe second transmitter unit can be configured to notify, to the mobilestation, the predetermined scheduling information via a downlink controlchannel.

In the fifth aspect, the persistent assignment signal, in the otherwords, the predetermined scheduling information can include at least oneof resource block assignment information, a modulation scheme, a datasize, MCS information, transmission format information, transmissionpower control information, information on Cyclic Shift of DemodulationRS, and a CQI request.

In the fifth aspect, the first transmitter unit can be configured todetermine the range on the basis of a data type.

Advantageous Effects of Invention

As described above, the present invention is capable of reducing theprobability of the occurrence of the False Alarm of uplink schedulinggrants in the “Persistent scheduling”. As a result, the presentinvention is capable of providing a stable and efficient mobilecommunication method, a mobile station, and a radio base station.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a functional block diagram of a mobile station according to afirst embodiment of the present invention.

FIG. 2 is a diagram for illustrating an uplink scheduling grant in amobile communication system according to the first embodiment of thepresent invention.

FIG. 3 is a diagram for illustrating scheduling performed in the mobilecommunication system according to the first embodiment of the presentinvention.

FIG. 4 is a functional block diagram of a radio base station accordingto the first embodiment of the present invention.

FIG. 5 is a flowchart showing operations of the mobile station accordingto the first embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS Configuration of Mobile Communication SystemAccording to First Embodiment of Present Invention

Referring to FIG. 1, a configuration of a mobile communication systemaccording to a first embodiment of the present invention is described.In this embodiment, a description is given using a mobile communicationsystem of the LTE scheme as an example, but the present invention isalso applicable to mobile communication systems of other modes.

In the mobile communication system according to the embodiment, a mobilestation UE is configured to transmit uplink data to a radio base stationeNB in a predetermined cycle by using a PUSCH (uplink radio resource)persistently assigned, the transmission starting at an assignmentstarting time.

Specifically, in the mobile communication system according to thisembodiment, a mobile station GE is configured to transmit uplink data toa radio base station by using an uplink radio resource assigned theretoin a predetermined cycle by predetermined scheduling information.

As shown in FIG. 1, the mobile station UE includes a Persistentinformation receiver unit 11, a Persistent assignment signal receiverunit 12, and an uplink data transmitter unit 13.

The Persistent information receiver unit 11 is configured to receive,from the radio base station eNB, Persistent information including thepredetermined cycle and the information on the uplink radio resource.

In addition, the Persistent information receiver unit 11 is configuredto notify, to the Persistent assignment signal receiver unit 12, theinformation on the uplink radio resource.

Specifically, the Persistent information receiver unit 11 is configuredto acquire the Persistent information, on the basis of an RRC messagetransmitted by the radio base station eNB.

Here, the information on an uplink radio resource is, for example,information for limiting a range of information to be notified by apersistent assignment signal (i.e., predetermined schedulinginformation) to be described later, i.e., a PDCCH (uplink schedulinggrant) giving an instruction of persistent assignment of a PUSCH (uplinkradio resource) for the “Persistent scheduling”.

Hereinafter, a description will be further given in detail.

The information elements of the PDCCH (uplink scheduling grant) givingthe instruction of persistent assignment are information elements asshown in FIG. 2, for example.

“Format Indicator” is information indicating whether the PDCCH isinformation for uplink or information for downlink. The information fordownlink is also called simplified downlink control information.

“Hopping flag” is information indicating whether or not hopping isapplied to an uplink signal the transmission of which is instructed bythe PDCCH.

“RB assignment information” is information indicating resource blockassignment information for the uplink signal the transmission of whichis instructed by the PDCCH.

“MCS information” is information on an MCS for the uplink signal thetransmission of which is instructed by the PDCCH. Here, the informationon the MCS is information such as a data size, a modulation scheme, anda Redundancy Version parameter in HARQ, for example.

“New Data Indicator” is information indicating whether the uplink signalthe transmission of which is instructed by the PDCCH is for newtransmission or retransmission.

“TPC” is information for uplink transmission power control for theuplink signal specified by the PDCCH.

“Cyclic shift for DMRS” is information on “Cyclic shift” of“Demodulation Reference signal” for the uplink signal specified by thePDCCH.

“CQI request” is information giving an instruction to transmit a CQI inthe uplink.

“RNTI/CRC” is CRC bits masked by an “UE-ID (RNTI)”.

Note that, the aforementioned information elements of the PDCCH (uplinkscheduling grant) are examples, and an information element other thanthe aforementioned information elements may be included in the PDCCH orsome of the aforementioned information elements may not be included inthe PDCCH.

In addition, the information on the uplink radio resource may beinformation for limiting the range of information to be notified by theaforementioned PDCCH (uplink scheduling grant) as described below.

For example, the information on the uplink radio resource may beinformation for limiting the range of information to be notified by theaforementioned “RB assignment information”.

More specifically, the information on the uplink radio resource may beinformation for limiting the number of resource blocks to be notified bythe aforementioned “RB assignment information”.

Further, the information on the uplink radio resource may be informationfor limiting the number of resource blocks to be notified by theaforementioned “RB assignment information” to “2” or “3”.

In this case, when the number of resource blocks notified by the PDCCH(uplink scheduling grant) is neither “2” nor “3”, the information on theuplink radio resource and the information (RB assignment information)notified by the PDCCH (uplink scheduling grant) are inconsistent witheach other.

Further, the information on the uplink radio resource may be informationfor limiting the number of resource blocks to be notified by theaforementioned “RB assignment information” to “3” or less.

Specifically, the information on the uplink radio resource may beinformation to indicate the maximum value of the number of resourceblocks to be notified by the aforementioned “RB assignment information”.

In this case, when the number of resource blocks notified by the PDCCH(uplink scheduling grant) is larger than “3”, the information on theuplink radio resource and the information (RB assignment information)notified by the PDCCH (uplink scheduling grant) are inconsistent witheach other.

Note that, the information on the uplink radio resource indicates themaximum value of the number of resource blocks notified by theaforementioned “RB assignment information” in the aforementionedexample, but the information on the uplink radio resource may indicatethe minimum value of the number of resource blocks instead.

Alternatively, the information on the uplink radio resource may indicateboth the maximum and minimum values of the number of resource blocks tobe notified by the aforementioned “RB assignment information”.

For example, the information on the uplink radio resource may indicate“10” as the maximum value of the number of resource blocks to benotified by the aforementioned “RB assignment information” and indicate“5” as the minimum value of the resource blocks.

In this case, when the number of resource blocks notified by the PDCCH(uplink scheduling grant) is larger than “10” or the number of theresource blocks is smaller than “5”, the information on the uplink radioresource and the information (RB assignment information) notified by thePDCCH (uplink scheduling grant) are inconsistent with each other.

Further, as far as the information on the uplink radio resource limitsthe range of information to be notified by the aforementioned “RBassignment information”, the method for limiting the range is notlimited to the aforementioned “limitation of the number of resourceblocks”, and the information may limit, by use of another limitationmethod, the range of information to be notified by the aforementioned“RB assignment information”.

For example, the information on the uplink radio resource may beinformation for limiting a position in a frequency direction of aresource block to be notified by the aforementioned “RS assignmentinformation”.

Alternatively, the information on the uplink radio resource may beinformation for limiting information to be notified by theaforementioned “MCS information”, for example. The information on theuplink radio resource may be information for limiting the range of amodulation scheme, a data size, or the like, for example.

More specifically, the information on the uplink radio resource may beinformation for limiting the modulation scheme to be notified by theaforementioned “MCS information”.

For example, the information on the uplink radio resource may beinformation for limiting the modulation scheme to be notified by theaforementioned “MCS information” to “QPSK”.

In this case, when the modulation scheme notified by the PDCCH (uplinkscheduling grant) is other than “QPSK”, for example, when the modulationscheme is “16QAM”, the information on the uplink radio resource and theinformation (MCS information) notified by the PDCCH (uplink schedulinggrant) are inconsistent with each other.

Note that, the aforementioned example illustrates an example in whichthe information on the uplink radio resource limits the modulationscheme to be notified by the “MCS information” to “QPSK”. However, theinformation on the uplink radio resource may limit the modulation schemeto be notified by the “MCS information” to “16QAM”, to “64QAM”, or tothe both of “QPSK” and “16QAM”, instead.

More specifically, the information on the uplink radio resource mayindicate whether it is applied or not on each of the modulation schemes,“QPSK”, “16QAM”, and “64QAM” to be notified by the “MCS information”.

Alternatively, the information on the uplink radio resource may beinformation for limiting a data size to be notified by the “MCSinformation”, for example.

For example, the information on the uplink radio resource may beinformation for limiting the data size to be notified by the “MCSinformation” to “320 bits”.

In this case, when the data size notified by the PDCCH (uplinkscheduling grant) is other than “320 bits”, e.g., when the data size is“512 bits”, the information on the uplink radio resource and theinformation (MCS information) notified by the PDCCH (uplink schedulinggrant) are inconsistent with each other.

Note that, the aforementioned value, “320 bits”, is only an example, andthe number of bits other than “320 bits” may be specified.

In addition, one kind of data size is specified in the aforementionedexample, but two or more kinds of data sizes may be specified.

Specifically, the information on the uplink radio resource may beinformation for limiting the data size notified by the “MCS information”to “320 bits” and “640 bits”, for example.

Alternatively, the information on the uplink radio resource may beinformation for limiting the data size notified by the “MCS information”to “320 bits” or less, for example.

In this case, when the data size notified by the PDCCH (uplinkscheduling grant) is larger than “320 bits”, e.g., when the data size is“512 bits”, the information on the uplink radio resource and theinformation (MCS information) notified by the PDCCH (uplink schedulinggrant) are inconsistent with each other.

Note that, the aforementioned value, “320 bits”, is only an example, andthe number of bits other than “320 bits” may be specified. In addition,the maximum value of the data size is specified in the aforementionedexample, but the minimum value of the data size may be specified,instead.

Alternatively, both of the maximum value and the minimum value of thedata size may be specified. For example, “640 bits” may be specified asthe maximum value of the data size, and “320 bits” may be specified asthe minimum value of the data size.

In this case, when the data size notified by the PDCCH (uplinkscheduling grant) is larger than “640 bits” or the data size is smallerthan “320 bits”, the information on the uplink radio resource and theinformation (MCS information) notified by the PDCCH (uplink schedulinggrant) are inconsistent with each other.

Note that, the aforementioned example shows a case where the informationnotified by “RB assignment information” or the information notified by“MCS information” is limited by the information on the uplink radioresource, but an information element other than the aforementionedelements may be limited by the information on the uplink radio resourceby the same method, instead.

In addition, “RB assignment information” or “MCS information” describedabove is information relating to resource blocks, or informationrelating to a modulation scheme or a data size, so that “RB assignmentinformation” or “MCS information” may be called “information relating totransmission format”.

The Persistent assignment signal receiver unit 12 is configured toreceive a persistent assignment signal from the radio base station eNB.

Specifically, the Persistent assignment signal receiver unit 12 isconfigured to receive, from the radio base station eNB, PDCCH (uplinkscheduling grant), as a persistent assignment signal, the PDCCH (uplinkscheduling grant) being transmitted to the mobile station itself andgiving an instruction to persistently assign a PUSCH (uplink radioresource) for the “Persistent scheduling”.

For example, the Persistent assignment signal receiver unit 12 may beconfigured to determine, on the basis of an RNTI or the like set in aPDCCH, whether or not a PDCCH (uplink scheduling grant) giving aninstruction of persistent assignment of a PUSCH (uplink radio resource)for the “Persistent scheduling” is transmitted to the mobile stationitself.

Instead, the Persistent assignment signal receiver unit 12 may beconfigured to determine, on the basis of an RNTI or the like set in aPDCCH, whether or not the received PDCCH is a PDCCH dynamicallyassigning a PUSCH (uplink radio resource), i.e., an uplink schedulinggrant for the dynamic scheduling.

Here, consider a case where, as a Persistent scheduling method in theLTE scheme, it is defined to determine on the basis of one specific bitin a PDCCH whether the PDCCH is a PDCCH (uplink scheduling grant) givingan instruction of persistent assignment of a PUSCH (uplink radioresource) for the “Persistent scheduling”, or a PDCCH dynamicallyassigning a PUSCH (uplink radio resource), i.e., an uplink schedulinggrant for the Dynamic scheduling. In this case, the Persistentassignment signal receiver unit 12 may be configured to determine on thebasis of the one bit whether the PDCCH is a PDCCH (uplink schedulinggrant) giving an instruction of persistent assignment of a PUSCH (uplinkradio resource) for the “Persistent scheduling”, or a PDCCH dynamicallyassigning a PUSCH (uplink radio resource), i.e., an uplink schedulinggrant for the Dynamic scheduling.

Alternatively, consider a case where, as a Persistent scheduling methodin an LTE scheme, it is defined that a part of the information elementsin a PDCCH indicates whether the PDCCH is a PDCCH (uplink schedulinggrant) giving an instruction of persistent assignment of a PUSCH (uplinkradio resource) for the “Persistent scheduling”, or a PDCCH dynamicallyassigning a PUSCH (uplink radio resource), i.e., an uplink schedulinggrant for Dynamic scheduling. In this case, the Persistent assignmentsignal receiver unit 12 may be configured to determine on the basis ofthe part of the information elements in the PDCCH whether the PDCCH is aPDCCH (uplink scheduling grant) giving an instruction of persistentassignment of a PUSCH (uplink radio resource) for the “Persistentscheduling”, or a PDCCH dynamically assigning a PUSCH (uplink radioresource), i.e., an uplink scheduling grant for Dynamic scheduling.

In addition, the Persistent assignment signal receiver unit 12 isconfigured to receive information on the uplink radio resource from thePersistent information receiver unit 11.

Here, the information on an uplink radio resource is, as describedabove, the information for limiting a range of information to benotified by the persistent assignment signal, i.e., a PDCCH (uplinkscheduling grant) giving an instruction of persistent assignment of aPUSCH (uplink radio resource) for the “Persistent scheduling”.

Further, the Persistent assignment signal receiver unit 12 determineswhether or not the information on the uplink radio resource and theinformation to be notified by the persistent assignment signal, i.e.,the PDCCH (uplink scheduling grant) giving an instruction of persistentassignment of a PUSCH (uplink radio resource) for the “Persistentscheduling” are inconsistent with each other.

When the Persistent assignment signal receiver unit 12 determines thatthe information on the uplink radio resource and the information to benotified by the persistent assignment signal, i.e., the PDCCH (uplinkscheduling grant) giving an instruction of persistent assignment of aPUSCH (uplink radio resource) for the “Persistent scheduling” areinconsistent with each other, the Persistent assignment signal receiverunit 12 discards the persistent assignment signal, i.e., the PDCCH(uplink scheduling grant) giving an instruction of persistent assignmentof a PUSCH (uplink radio resource) for the “Persistent scheduling”,which the Persistent assignment signal receiver unit 12 has determinedas the signal transmitted to the mobile station itself.

Specifically, in this case, the Persistent assignment signal receiverunit 12 regards that the information notified by the persistentassignment signal, i.e., the PDCCH (uplink scheduling grant) giving aninstruction of persistent assignment of a PUSCH (uplink radio resource)for the “Persistent scheduling” has not been transmitted to the mobilestation itself.

In the aforementioned processing, the Persistent assignment signalreceiver unit 12 provides the uplink data transmitter unit 13 with thepersistent assignment signal which is not discarded, i.e., the PDCCH(uplink scheduling grant) giving an instruction of persistent assignmentof a PUSCH (uplink radio resource) for the “Persistent scheduling”.

Hereinafter, an example will be shown of the processing as describedabove to discard the persistent assignment signal, i.e., the PDCCH(uplink scheduling grant) giving an instruction of persistent assignmentof a PUSCH (uplink radio resource) for the “Persistent scheduling”.

Consider a case where the information on the uplink radio resource isinformation to limit the number of resource blocks to be notified by the“RB assignment information” to “2” or “3”, for example. When the numberof resource blocks notified by the PDCCH (uplink scheduling grant) isneither “2” nor “3” in this case, the Persistent assignment signalreceiver unit 12 determines that the information on the uplink radioresource and the information (RB assignment information) notified by thePDCCH (uplink scheduling grant) are inconsistent with each other. Thus,the PDCCH (uplink scheduling grant) is discarded.

Alternatively, consider a case where the information on the uplink radioresource is information to limit the number of resource blocks to benotified by the “RB assignment information” to “3” or less, for example.When the number of resource blocks notified by the POOCH (uplinkscheduling grant) is larger than “3” in this case, e.g., when the numberof resource blocks is “5”, the Persistent assignment signal receiverunit 12 determines that the information on the uplink radio resource andthe information (RB assignment information) notified by the PDCCH(uplink scheduling grant) are inconsistent with each other. Thus, thePDCCH (uplink scheduling grant) is discarded.

Alternatively, consider a case where the information on the uplink radioresource is information to limit the number of resource blocks to benotified by the “RB assignment information” to “10” or less, but atleast “5”, for example. When the number of resource blocks notified bythe POOCH (uplink scheduling grant) is larger than “10” or smaller than“5” in this case, e.g., when the number of resource blocks is “12”, thePersistent assignment signal receiver unit 12 determines that theinformation on the uplink radio resource and the information (RBassignment information) notified by the POOCH (uplink scheduling grant)are inconsistent with each other. Thus, the PDCCH (uplink schedulinggrant) is discarded.

Alternatively, consider a case where the information on the uplink radioresource is information to limit the modulation scheme to be notified bythe “MCS information” to “QPSK”, for example. When the modulation schemenotified by the PDCCH (uplink scheduling grant) is not “QPSK” in thiscase, e.g., when the modulation scheme is “16QAM”, the Persistentassignment signal receiver unit 12 determines that the information onthe uplink radio resource and the information (MCS information) notifiedby the POOCH (uplink scheduling grant) are inconsistent with each other.Thus, the PDCCH (uplink scheduling grant) is discarded.

Alternatively, consider a case where the information on the uplink radioresource is information to limit the data size to be notified by the“MCS information” to “320 bits”, for example. When the data sizenotified by the PDCCH (uplink scheduling grant) is not “320 bits” inthis case, e.g., when the data size is “1024 bits”, the Persistentassignment signal receiver unit 12 determines that the information onthe uplink radio resource and the information (MCS information) notifiedby the PDCCH (uplink scheduling grant) are inconsistent with each other.Thus, the POOCH (uplink scheduling grant) is discarded.

Alternatively, consider a case where the information on the uplink radioresource is information to limit the data size to be notified by the“MCS information” to “320 bits” or less, for example. When the data sizenotified by the PDCCH (uplink scheduling grant) is larger than “320bits” in this case, e.g., when the data size is “512 bits”, thePersistent assignment signal receiver unit 12 determines that theinformation on the uplink radio resource and the information (MCSinformation) notified by the PDCCH (uplink scheduling grant) areinconsistent with each other. Thus, the PDCCH (uplink scheduling grant)is discarded.

Alternatively, consider a case where the information on the uplink radioresource is information to limit the data size to be notified by the“MCS information” to “640 bits” or less, but at least “320 bits”, forexample. When the data size notified by the PDCCH (uplink schedulinggrant) is larger than “640 bits”, or smaller than “320 bits” in thiscase, e.g., when the data size is “1024 bits”, the Persistent assignmentsignal receiver unit 12 determines that the information on the uplinkradio resource and the information (MCS information) notified by thePDCCH (uplink scheduling grant) are inconsistent with each other. Thus,the POOCH (uplink scheduling grant) is discarded.

Note that, in the aforementioned example, the Persistent assignmentsignal receiver unit 12 determines whether or not the information on theuplink radio resource and the information to be notified by thepersistent assignment signal, i.e., the PDCCH (uplink scheduling grant)giving an instruction of persistent assignment of a PUSCH (uplink radioresource) for the “Persistent scheduling” are inconsistent with eachother. Instead, the Persistent assignment signal receiver unit 12 maydetermine whether or not an inconsistency other than the aforementionedinconsistencies exists. Then, when determining that such aninconsistency exists, the Persistent assignment signal receiver unit 12may discard the persistent assignment signal, i.e., the PDCCH (uplinkscheduling grant) giving an instruction of persistent assignment of aPUSCH (uplink radio resource) for the “Persistent scheduling”.

For example, consider a case where the mobile station does not have acapability to support uplink “64QAM” transmission. When the Persistentassignment signal receiver unit 12 is given an instruction for “64QAM”transmission by the persistent assignment signal, i.e., the PDCCH(uplink scheduling grant) giving an instruction of persistent assignmentof a PUSCH (uplink radio resource) for the “Persistent scheduling” inthis case, the Persistent assignment signal receiver unit 12 may discardthe persistent assignment signal, i.e., the PDCCH (uplink schedulinggrant) giving an instruction of persistent assignment of a PUSCH (uplinkradio resource) for the “Persistent scheduling”.

Alternatively, consider a case where the mobile station has a capabilityto allow the maximum transmittable data size of “10000 bits”. When thePersistent assignment signal receiver unit 12 is given an instructionfor transmission of an uplink signal with a data size of “20000 bits” bythe persistent assignment signal, i.e., the PDCCH (uplink schedulinggrant) giving an instruction of persistent assignment of a PUSCH (uplinkradio resource) for the “Persistent scheduling”, the Persistentassignment signal receiver unit 12 may discard the persistent assignmentsignal, i.e., the PDCCH (uplink scheduling grant) giving an instructionof persistent assignment of a PUSCH (uplink radio resource) for the“Persistent scheduling”.

Meanwhile, generally, there is a bit pattern having no meaning asinformation in the persistent assignment signal, i.e., the PDCCH (uplinkscheduling grant) giving an instruction of persistent assignment of aPUSCH (uplink radio resource) for the “Persistent scheduling”.

Accordingly, when some bit pattern of the persistent assignment signal,i.e., the PDCCH (uplink scheduling grant) giving an instruction ofpersistent assignment of a PUSCH (uplink radio resource) for the“Persistent scheduling” has no meaning as information, the Persistentassignment signal receiver unit 12 may discard the persistent assignmentsignal, i.e., the PDCCH (uplink scheduling grant) giving an instructionof persistent assignment of a PUSCH (uplink radio resource) for the“Persistent scheduling”.

Note that, the expression “a bit pattern has no meaning as information”may be expressed differently that the bit pattern is not supposed to benotified.

In this case, the Persistent assignment signal receiver unit 12 maydetermine, regardless of the information on the uplink radio resource,whether or not some bit pattern of the persistent assignment signal,i.e., of the PDCCH (uplink scheduling grant) giving an instruction ofpersistent assignment of a PUSCH (uplink radio resource) for the“Persistent scheduling” has meaning as information as described above.

Alternatively, the Persistent assignment signal receiver unit 12 maydetermine whether or not some bit pattern of the persistent assignmentsignal, i.e., of the PDCCH (uplink scheduling grant) giving aninstruction of persistent assignment of a PUSCH (uplink radio resource)for the “Persistent scheduling” has meaning as information as describedabove, in a case where the information on the uplink radio resource doesnot exist.

Here, an example of the aforementioned “bit pattern not supposed to benotified” will be described.

For example, when the value of the number of RBs indicated by “RBassignment information” shown in FIG. 2 is defined to be always “10” orless in the persistent assignment signal, a bit pattern indicating avalue larger than “10” as the number of RBs shown by the “RB assignmentinformation” is considered to be a bit pattern not supposed to benotified.

Specifically, the mobile station UE discards the persistent assignmentsignal, when the value of the number of RBs indicated by the “RBassignment information” in the persistent assignment signal is largerthan “10”.

Alternatively, in a case where the value of the data size indicated by“MCS information” shown in FIG. 2 is defined to be always “1000” or lessin the persistent assignment signal, for example, a bit patternindicating a value larger than “1000” as the data size shown by the “MCSinformation” is considered to be a bit pattern not supposed to benotified.

Specifically, the mobile station UE discards the persistent assignmentsignal, when the value of the data size indicated by the “MCSinformation” in the persistent assignment signal is larger than “1000”.

Note that, the case where the value of the data size indicated by the“MCS information” is larger than “1000” may mean that a part of bits ofthe “MCS information” is not a predetermined value, for example. Inacase where the data size is defined by a four-digit binary number(described as “abcd” hereinafter where the first digit “a” correspondsto the “Most Significant bit”), the data size is described as followswhen expressed by a decimal number.(Data size expressed by a decimal number)=2³ ×a+2² ×b+2¹ ×c+2⁰ ×d

Here, when “a”, which is the “Most Significant bit”, is not “0”, i.e.,when “a” is “1”, the data size is at least “8”.

Specifically, the mobile station UE may discard the persistentassignment signal, when a part of the bits of the “MCS information” inthe persistent assignment signal is not a predetermined value.

More specifically, the mobile station UE may discard the persistentassignment signal, when the “Most Significant bit” of the “MCSinformation” in the persistent assignment signal is not a predeterminedvalue (when the “Most Significant bit” is not “0” in the aforementionedexample, for example), or a predetermined number of bits consecutivefrom the “Most Significant bit” are not a predetermined value (forexample, when neither “a” nor “b” is “0”, suppose that the values of twoconsecutive bits are not a predetermined value in the aforementionedexample).

Note that, the same processing may be applied when the “MCS information”indicates both of the data size and modulation scheme.

Alternatively, when the modulation scheme indicated by the “MCSinformation” shown in FIG. 2 is defined to be always “QPSK” in thepersistent assignment signal, for example, a bit pattern indicating“16QAM” or “64QAM” as the modulation scheme shown by the “MCSinformation” is considered to be a bit pattern not supposed to benotified.

Specifically, the mobile station US discards the persistent assignmentsignal, when the modulation scheme indicated by the “MCS information” inthe persistent assignment signal is not “QPSK”.

Alternatively, the persistent assignment signal is basically a signalgiving an instruction for new transmission. Thus, a bit patternspecifying a modulation scheme used in retransmission in the “MCSinformation”, for example, is considered to be a bit pattern notsupposed to be notified.

Specifically, the mobile station US discards the persistent assignmentsignal, when the “MCS information” in the persistent assignment signalindicates a bit pattern specifying a modulation scheme used inretransmission.

Alternatively, when it is defined that “1” is always set in thepersistent assignment signal as the value of “TPC” shown in FIG. 2, forexample, “0” as the value of “TPC” is considered to be a bit pattern notsupposed to be notified.

Specifically, the mobile station UE discards the persistent assignmentsignal, when the value of “TPC” in the persistent assignment signal is“0”.

Note that, the number of bits for “TPC” is “1” in the aforementionedexample, but the number of bits may be other than “1”, e.g., “2” or “3”.For example, when the number of bits for “TPC” is “2”, and it is definedthat “11” is always set as the value of TPC, bit patterns “10”, “01”,and “00” are considered to be bit patterns not supposed to be notified.

Alternatively, when it is defined that “1” is always set as the value of“Cyclic Shift for DMRS” shown in FIG. 2 in the persistent assignmentsignal, for example, “0” as the value of the “Cyclic Shift for DMRS” isconsidered to be a bit pattern not supposed to be notified.

Specifically, the mobile station UE discards the persistent assignmentsignal, when the value of the “Cyclic Shift for DMRS” in the persistentassignment signal is “0”.

Note that, the number of bits for the “Cyclic Shift for DMRS” in theaforementioned example is “1”, but the number of bits may be a valueother than “1”, e.g., “2” or “3”.

Alternatively, when it is defined that “1” is always set as the value of“CQI request” shown in FIG. 2 in the persistent assignment signal, forexample, “0” as the value of the “CQI request” is considered to be a bitpattern not supposed to be notified.

Specifically, the mobile station UE discards the persistent assignmentsignal, when the value of the “CQI request” in the persistent assignmentsignal is “0”.

Alternatively, when it is defined that “1” is always set as the value of“New Data Indicator” shown in FIG. 2 in the persistent assignmentsignal, for example, “0” as the value of the “New Data Indicator” isconsidered to be a bit pattern not supposed to be notified.

Specifically, the mobile station UE discards the persistent assignmentsignal, when the value of the “New Data Indicator” in the persistentassignment signal is “0”.

Alternatively, the mobile station UE may identify the aforementioned“bit pattern not supposed to be notified”, on the basis of informationin a persistent assignment signal received in the past.

For example, when the data size indicated by “MCS information” in apersistent assignment signal received in the past is always “320 bits”,the mobile station UE may regard a bit pattern indicating a data sizeother than “320 bits” as a bit pattern not supposed to be notified.

Here, for example, it is considered that “False Alarm” happens when themobile station UE is in a state where it has not received a correctpersistent assignment signal even once in the past. Consider a casewhere the mobile station UE has received a persistent assignment signalhaving the same data size at least “three times” in the past. In thiscase, the mobile station UE may regard a bit pattern showing a data sizeother than the aforementioned data size as a bit pattern not supposed tobe notified.

Alternatively, in a case where the mobiles station UE has consecutivelyreceived a persistent assignment signal having the same data size atleast “three times” in the past, the mobile station UE may regard a bitpattern showing a data size other than the aforementioned data size as abit pattern not supposed to be notified.

Note that, the numbers shown in the aforementioned example such as “320bits” and “three times” are only examples, and the numbers may be valuesother than the values shown in the aforementioned example.

Note that, multiple of the aforementioned processing operations todiscard the PDCCH (uplink scheduling grant) giving an instruction ofpersistent assignment of a PUSCH (uplink radio resource) for the“Persistent scheduling” may be applied simultaneously.

Specifically, when multiple processing operations to discard the PDCCHgiving the instruction of persistent assignment are performed, and whenthe PDCCH is determined to be discarded in at least one of theprocessing operations, the processing operation to discard the PDCCH maybe performed.

The uplink data transmitter unit 13 is configured to transmit uplinkdata to be transmitted via a PUSCH (uplink radio resource) assigned by aPDCCH.

Specifically, the uplink data transmitter unit 13 is configured todetermine an uplink transmission sub-frame as the aforementioned“assignment starting time”, when receiving from the Persistentassignment signal receiver unit 12, the aforementioned Persistentassignment signal, i.e., the PDCCH (uplink scheduling grant) giving theinstruction of persistent assignment of a PUSCH (uplink radio resource)for the “Persistent scheduling”, the uplink transmission sub-framespecified by the PDCCH. The uplink data transmitter unit 13 isconfigured then to start persistent transmission of the uplink data viathe PUSCH (uplink radio resource) for the “Persistent scheduling” in theaforementioned “predetermined cycle” at the “assignment starting time”.

In the example shown in FIG. 3, the uplink data transmitter unit 13 isconfigured to transmit, once the Persistent assignment signal receiverunit 12 has received the persistent assignment signal in a sub-frame #3via the PDCCH, the uplink data via a PUSCH (uplink radio resource)mapped to a resource block (aggregate of sub-carriers) in an uplinktransmission sub-frame #7 specified by the PDCCH.

Furthermore, the uplink data transmitter unit 13 is configured totransmit uplink data via a PUSCH (uplink radio resource) mapped to aresource block (aggregate of sub-carriers) specified by the PDCCH in thecycle of 20 ms, the transmission starting at the sub-frame #7.

That is, the uplink data transmitter unit 13 is configured to transmituplink data via a PUSCH (uplink radio resource) mapped to a resourceblock (aggregate of sub-carriers) specified by the POOCH in sub-frames#7, #27, 447, . . . .

On the other hand, the radio base station eNB according to the presentinvention is configured to notify, to the mobile station UE, thepredetermined cycle and the information on an uplink radio resource.

Since the description related to such information as the information onthe uplink radio resource is the same as the description given for themobile station UE, the description thereof is omitted herein.

As shown in FIG. 4, the radio base station eNB includes a Persistentinformation transmitter unit 21, a Persistent assignment signaltransmitter unit 22, and an uplink data receiver unit 23.

The Persistent information transmitter unit 21 is configured totransmit, to the mobile station UE, Persistent information (persistentcommunication information) including the predetermined cycle andinformation on an uplink radio resource.

Specifically, the Persistent information transmitter unit 21 isconfigured to notify, to the mobile station UE, the Persistentinformation by using an RRC message.

Here, the information on the uplink radio source is the information forlimiting a range of information to be notified by a persistentassignment signal, i.e., a PDCCH (uplink scheduling grant) giving aninstruction of persistent assignment of a PUSCH (uplink radio resource)for the “Persistent scheduling”.

Since the description of the information on the uplink radio resource isthe same as the description given for the mobile station UE, thedescription thereof is omitted herein.

Here, the Persistent information transmitter unit 21 may set informationon the uplink radio resource on the basis of a data type.

For example, when the data type is VoIP, the Persistent informationtransmitter unit 21 may set the information on the uplink radio resourceto be information to limit the number of resource blocks to be notifiedby the “RB assignment information” to “3” or less. In addition, when thedata type is streaming, the Persistent information transmitter unit 21may set the information on the uplink radio resource to be informationto limit the number of resource blocks to be notified by the “RBassignment information” to “10” or less.

Alternatively, when the data type is VoIP, the Persistent informationtransmitter unit 21 may set the information on the uplink radio resourceto be information to limit the modulation scheme to be notified by the“MCS information” to “QPSK”. In addition, when the data type isstreaming, the Persistent information transmitter unit 21 may set theinformation on the uplink radio resource to be information to limit themodulation scheme to be notified by the “MCS information” to “QPSK” or“16QAM”.

Alternatively, when the data type is VoIP, the Persistent informationtransmitter unit 21 may set the information on the uplink radio resourceto be information to limit the data size to be notified by the “MCSinformation” to “320 bits”. In addition, when the data type isstreaming, the Persistent information transmitter unit 21 may set theinformation on the uplink radio resource to be information to limit thedata size to be notified by the “MCS information” to “640 bits”.

Specifically, how the information to be notified by the persistentassignment signal, i.e., the PDCCH (uplink scheduling grant) giving aninstruction of persistent assignment of a PUSCH (uplink radio resource)for the “Persistent scheduling” is limited may be determined on thebasis of a data type of data for which the resource is assigned by thePersistent scheduling.

Note that, the aforementioned “data type” may be termed as a “servicetype”. Specifically, the “service type” is information indicating a typeof packet transmission service. Thus, the “service type” may include aVoIP service, voice service, streaming service, FTP (File TransferProtocol) service, and the like, for example.

In the aforementioned example, the Persistent information transmitterunit 21 sets information on the uplink radio resource on the basis of a“data type”, but may set information on the uplink radio resource on thebasis of a “contract type”, a “logical channel type”, a “cell type”, ora “priority type” instead of the “data type”.

In addition, the “contract type” shows a type of contract subscribed bythe user of the mobile station UE and includes a Low Class contract orHigh Class contract, or a flat rate contract or volume charging contractor the like, for example.

In addition, the “cell type” shows an operation situation of the cell,and an indoor or outdoor situation, and an urban area or rural areasituation are conceivable.

The “logical channel type” is a type of logical channel such asDedicated Control Channel (DCCH) or Dedicated Traffic Channel (DTCH).Multiple channels may be further defined in the DCCH or DTCH.

Here, “Radio Bearer” means a bearer that transmits data and is definedto have a one-to-one relationship with a logical channel through whichthe data is transmitted. As a result, the bearer has approximately thesame meaning as the logical channel.

The “priority type” is a class to categorize priorities relating touplink and downlink data transmission into classes. For example, datawith a first priority class is transmitted more preferentially than datawith a second priority class.

The “priority type” may be combined with a logical channel, and thencalled a “Logical Channel Priority”. Alternatively, the “priority type”may be defined as “Priority Class”.

The Persistent assignment signal transmitter unit 22 is configured totransmit a persistent assignment signal to the mobile station UE.

Specifically, the Persistent assignment signal transmitter unit 22 isconfigured to transmit, to the mobile station UE, the PDCCH (uplinkscheduling grant) giving an instruction of persistent assignment of aPUSCH (uplink radio resource) for the “Persistent scheduling”, as apersistent assignment signal.

Note that, when it is defined that “1” is always set as the value of“TPC (refer to FIG. 2)” in the persistent assignment signal as describedabove, the Persistent assignment signal transmitter unit 22 may alwaysset “1” as the value of the “TPC”.

Alternatively, when it is defined that “1” is always set as the value of“Cyclic Shift for DMRS (refer to FIG. 2)” in the persistent assignmentsignal as described above, for example, the Persistent assignment signaltransmitter unit 22 may always set “1” as the value of the “Cyclic Shiftfor DMRS”.

Alternatively, when it is defined that “1” is always set as the value of“CQI request (refer to FIG. 2)” in the persistent assignment signal asdescribed above, for example, the Persistent assignment signaltransmitter unit 22 may always set “1” as the value of the “CQIrequest”.

Alternatively, when it is defined that “1” is always set as the value of“New Data Indicator (refer to FIG. 2)” in the persistent assignmentsignal as described above, for example, the Persistent assignment signaltransmitter unit 22 may always set “1” as the value of the “New DataIndicator”.

The uplink data receiver unit 23 is configured to receive uplink data tobe transmitted via a PUSCH (uplink radio resource) assigned by a PDCCH.

Specifically, the uplink data receiver unit 23 is configured todetermine the uplink transmission sub-frame specified by the PDCCH to bethe aforementioned “assignment starting time” when the aforementionedPersistent assignment signal is transmitted by the Persistent assignmentsignal transmitter unit 22. The uplink data receiver unit 23 isconfigured then to start persistent reception of the uplink data via thePUSCH (uplink radio resource) for the “Persistent scheduling” in theaforementioned “predetermined cycle”, the reception starting at the“assignment starting time”.

Operation of Mobile Communication System According to First Embodimentof Present Invention

Referring to FIG. 5, an operation of the mobile communication systemaccording to the first embodiment of the present invention is described.

As shown in FIG. 5, in step S101, the mobile station UE receives, by wayof an RRC message or the like, Persistent information including theaforementioned predetermined cycle and the information on the uplinkradio resource from the radio base station eNB.

Note that, the information on the uplink radio resource is, for example,information for limiting a range of information to be notified by apersistent assignment signal, i.e., a PDCCH (uplink scheduling grant)giving an instruction of persistent assignment of a PUSCH (uplink radioresource) for the “Persistent scheduling”.

The description of the information on the uplink radio resource is thesame as that for the mobile station UE. Thus, the description thereof isomitted herein.

In the step S102, the mobile station UE receives the Persistentassignment signal transmitted by the radio base station eNB via thePDCCH.

More specifically, the mobile station UE receives, as the persistentassignment signal, a PDCCH (uplink scheduling grant) giving aninstruction of persistent assignment of a PUSCH (uplink radio resource)for the “Persistent scheduling” from the radio base station eNB.

In step S103, the mobile station UE determines whether or not theinformation on the uplink radio resource and the information notified bythe persistent assignment signal, i.e., the PDCCH (uplink schedulinggrant) giving an instruction of persistent assignment of a PUSCH (uplinkradio resource) for the “Persistent scheduling” are inconsistent witheach other.

Here, a detailed description of the aforementioned processing todetermine whether or not an inconsistency exists is omitted hereinbecause the description thereof is the same as that in the case of themobile station UE.

In a case where the mobile station UE determines that the information onthe uplink radio resource and the information notified by the persistentassignment signal, i.e., the PDCCH (uplink scheduling grant) giving aninstruction of persistent assignment of a PUSCH (uplink radio resource)for the “Persistent scheduling” are inconsistent with each other (stepS103: YES), the operation proceeds to step S104.

In step S104, the mobile station UE discards the persistent assignmentsignal, i.e., the PDCCH (uplink scheduling grant) giving an instructionof persistent assignment of a PUSCH (uplink radio resource) for the“Persistent scheduling”.

Specifically, the mobile station UE regards the information notified bythe persistent assignment signal, i.e., the PDCCH (uplink schedulinggrant) giving an instruction of persistent assignment of a PUSCH (uplinkradio resource) for the “Persistent scheduling” as information that hasnot been transmitted to the mobile station UE itself.

In step S105, the mobile station UE determines an uplink transmissionsub-frame as the aforementioned assignment starting time, the uplinktransmission sub-frame specified by the aforementioned Persistentassignment signal, i.e., the PDCCH (uplink scheduling grant) giving aninstruction of persistent assignment of a PUSCH (uplink radio resource)for the “Persistent scheduling”. The mobile station UE then startspersistent uplink data transmission via the PUSCH (uplink radioresource) for the “Persistent scheduling” in the aforementionedpredetermined cycle, the transmission starting at the assignmentstarting time in step S105.

Specifically, in this case, the mobile station UE performs the uplinkdata transmission via the PUSCH (uplink radio resource) for the“Persistent scheduling”, until the aforementioned PUSCH (uplink radioresource) for the “Persistent scheduling” is released.

Advantageous Effect of Mobile Communication System According to FirstEmbodiment of the Present Invention

As described above, the probability of the occurrence of the False Alarmfor one PDCCH (uplink scheduling grant or downlink scheduling grantinformation) is ½¹⁶.

In general, the mobile station UE attempts to decode about 40 PDCCHs ina single sub-frame, the total probability of the occurrence of the FalseAlarm is calculated as 40×½¹⁶=0.0006.

Here, the False Alarm described above is a phenomenon in which themobile station UE incidentally determines that a PDCCH is transmitted tothe mobile station UE itself although the PDCCH is not transmitted tothe mobile station UE itself. Thus, the decoded information in this caseis highly likely to be nonsense information.

Accordingly, as described above, a limitation is provided in the rangeof information in a PDCCH, and when the mobile station UE receives aPDCCH having information outside the limited range, the mobile stationUE performs processing to discard the PDCCH. Thus, the probability ofthe occurrence of the False Alarm can be significantly reduced.

For example, suppose that the number of bits in a PDCCH other than CRCis 24 bits, and a 12-bit range among the 24 bits in the PDCCH islimited. For the sake of simplicity of calculation, suppose that the bitpattern of 12 bits is limited to a single kind.

In this case, as described above, a limitation is provided in the rangeof information in the PDCCH, and when the mobile station UE receives aPDCCH having information outside the limited range, the mobile stationUE performs processing to discard the PDCCH. Thus, the probability ofthe occurrence of the False Alarm is calculated as follows:40×½¹⁶×½¹²/2²⁴=1.5×10⁻⁷.

Thus, the probability of the occurrence of False Alarm is made muchsmaller in this case.

Specifically, the mobile communication system according to the firstembodiment of the present invention is capable of reducing theprobability of the occurrence of the “False Alarm” of a PDCCH (uplinkscheduling grant) indicating a resource assignment for the Persistentscheduling. As a result, the mobile communication system according tothe first embodiment of the present invention is capable of providing astable and efficient mobile communication method, a mobile station, anda radio base station.

MODIFICATION

Note that operation of the above described mobile station UE and theradio base station eNB may be implemented by means of hardware, asoftware module executed by a processor, or a combination of both.

The software module may be provided in any type of storage medium suchas an RAM (Random Access Memory), a flash memory, a ROM (Read OnlyMemory), an EPROM (Erasable Programmable ROM), an EEPROM (ElectronicallyErasable and Programmable ROM), a register, a hard disk, a removabledisk, or a CD-ROM.

The storage medium is connected to the processor so that the processorcan read and write information from and to the storage medium. Also, thestorage medium may be integrated into the processor. Also, the storagemedium and the processor may be provided in an ASIC. The ASIC may beprovided in the mobile station UE and the radio base station eNB. Also,the storage medium and the processor may be provided in the mobilestation UE and the radio base station eNB as a discrete component.

Hereinabove, the present invention has been described in detail usingthe above embodiment; however, it is apparent to those skilled in theart that the present invention is not limited to the embodimentdescribed herein. Modifications and variations of the present inventioncan be made without departing from the spirit and scope of the presentinvention defined by the description of the scope of claims. Thus, whatis described herein is for illustrative purpose, and has no intentionwhatsoever to limit the present invention.

The invention claimed is:
 1. A mobile communication method in which amobile station transmits an uplink signal to a radio base station, themethod comprising the steps: receiving an uplink scheduling grant forsemi-persistent scheduling as predetermined scheduling information fromthe radio base station; and transmitting an uplink signal on the basisof the received uplink scheduling grant without receiving any uplinkscheduling grant dynamically assigning an uplink radio resource, whereinthe mobile station discards the uplink scheduling grant and does notstart transmitting the uplink signal so as to reduce a probability of anoccurrence of a false alarm in uplink scheduling grant forsemi-persistent scheduling when a value of an information element“Cyclic Shift for DMRS” in the uplink scheduling grant does not match apredefined fixed value.
 2. A mobile station configured to transmit anuplink signal to a radio base station, the mobile station comprising: acommunication unit configured to transmit an uplink signal on the basisof an uplink scheduling grant for semi-persistent scheduling receivedfrom the radio base station as predetermined scheduling informationwithout receiving any uplink scheduling grant dynamically assigning anuplink radio resource, wherein the communication unit is configured todiscard the uplink scheduling grant and does not start transmitting theuplink signal when a value of an information element “Cyclic Shift forDMRS” in the uplink scheduling grant does not match a predefined fixedvalue.
 3. A mobile communication method in which a mobile stationtransmits uplink data to a radio base station by using an uplink radioresource assigned to the mobile station by predetermined schedulinginformation instructing semi-persistent assignment of the uplink radioresource, in a predetermined cycle, the method comprising the steps:receiving the predetermined cycle from the radio base station; receivingthe predetermined scheduling information from the radio base station;and transmitting uplink data in the predetermined cycle by using theuplink radio resource assigned by the predetermined schedulinginformation without receiving any uplink scheduling grant dynamicallyassigning an uplink radio resource, the transmission starting at acertain point determined on the basis of the received predeterminedscheduling information, wherein the predetermined scheduling informationis discarded and the transmission is not started so as to reduce aprobability of an occurrence of a false alarm in uplink scheduling grantfor semi-persistent scheduling, when the information included in thepredetermined scheduling information does not match at least one ofpreviously defined “MCS information,” “TPC,” and “HARQ processinformation.”
 4. A mobile station configured to transmit uplink data toa radio base station by using an uplink radio resource assigned to themobile station by predetermined scheduling information instructingsemi-persistent assignment of the uplink radio resource, in apredetermined cycle, the mobile station comprising: a receiver unitconfigured to receive the predetermined cycle from the radio basestation; and a communication unit configured to transmit uplink data inpredetermined cycle by using the uplink radio resource assigned by thepredetermined scheduling information without receiving any uplinkscheduling grant dynamically assigning an uplink radio resource, thetransmission starting at a certain point determined on the basis of thepredetermined scheduling information received from the radio basestation, wherein the communication unit is configured to discard thepredetermined scheduling information and not to start the transmission,when the information included in the predetermined schedulinginformation does not match at least one of previously defined “MCSinformation,” “TPC,” and “HARQ process information.”